UD5 Toolkit
Scale of the Universe - Online Zoom from Planck to Galaxy
Zoom through sizes from the Planck length to the observable universe. Educational and aweâinspiring visualization.
Educational Tools - School & Teaching
99+ toolsMagic Square Generator - Online Create n x n Constant Sum Grid
Generate magic squares of odd order (3x3, 5x5, âŠ). See the sum constant and verify rows, columns, diagonals. Educational math toy.
Emoji Cipher Decoder - Online Secret Message Fun
Decode a message hidden in a string of emojis (each emoji maps to a letter). Fun game for kids. Create your own.
Planetary Fact Sheet - Online Solar System Stats
Click a planet to see mass, diameter, moons, temperature, and distance from sun. Beautifully styled static data.
Pi Digits Viewer - Online Scrolling Infinite Ï
Scroll through thousands of preâcomputed digits of Ï. Search for a specific string of digits. For math lovers.
Tangram Puzzle - Online Drag & Match Shapes
Drag the seven tangram pieces to form a target silhouette. Multiple puzzles. Develop spatial thinking. All canvas interactions.
Alphabet of Elements - Online AâZ by Chemistry Symbol
See all elements sorted alphabetically by symbol. Picture and atomic weight. Beautifully styled static list.
ASL Fingerspelling Practice - Online Random Words Quiz
Shows a random short word and displays animated ASL fingerspelling letters. Type what you see. Improve receptive skills.
Julian Date Converter - Online Calendar to JD
Convert a Gregorian calendar date to its Julian Day Number and vice versa. Used in astronomy and mainframe computing.
Image FFT Visualizer - Online See Frequency Domain
Upload an image and see its 2D FFT magnitude and phase. Learn how image filtering works. Educatinal tool. Canvas.
Bayes' Theorem Calculator - Online Probability Update Tool
Easily compute posterior probabilities given prior, likelihood, and marginal likelihood. Visual diagram. All local.
Day of the Week Calculator - Online Find Weekday from Date
Find what day of the week any past or future date falls on. Uses Zellerâs congruence. Fun historical reference tool.
Online Scientific Calculator - Free Advanced Math Tool
Full-featured scientific calculator with trigonometric, logarithmic, and exponential functions. Clean interface and keyboard support. No installation required.
Polygon Centroid Calculator - Online Center of Mass
Find the centroid (center of mass) of any convex polygon by entering vertex coordinates. Useful for physics and design.
Roman Numeral Date Converter - Online MMXXVI Style
Convert any date into Roman numerals (dayâmonthâyear) for tattoos or special occasions. Clean and local.
Flexbox Froggy Simulator - Online Learn CSS Flexbox Game
A replica of the famous Flexbox Froggy game: solve alignment puzzles by writing CSS. Progress saved locally. Fun frontend learning.
Elephant Toothpaste Demo Calculator - Online Reaction Ratios
Find safe mixing ratios for the classic elephant toothpaste demonstration. Volume adjustments for different container sizes.
Radiation Converter - Online Gray Rad Rem & Sievert
Convert between units of absorbed dose and equivalent dose (Gray, Rad, Rem, Sievert). Educational and reference. Local calculation.
Text to Anki CSV - Online Flashcard Converter
Format a list of Q&A pairs and export as a CSV ready for Anki import. Simple lineâbased template. Local.
ASL Alphabet Quiz - Online Fingerspelling Practice
Test your knowledge of American Sign Language letters. See a sign and type the letter. Improve receptive skills. Local.
Camera Exposure Simulator - Online Learn ISO, Aperture, Shutter
Adjust ISO, aperture, and shutter speed sliders and see how it affects the exposure of a sample scene. Learn photography basics.
Signed Magnitude Converter - Online Negative Binary Numbers
Encode decimal integers into signed magnitude binary representation and decode back. Learn computer arithmetic.
Polygon Area Calculator - Online Irregular Shape Tool
Calculate the area of an irregular polygon by entering its vertex coordinates. Uses the shoelace formula. Pure math.
Spirograph Simulator - Online Hypocycloid Drawing Tool
Create beautiful Spirograph patterns by adjusting circle radii and pen position. Change colors and save as PNG. Relaxing math art.
pH Scale Explorer - Online Interactive Acid Base Chart
Drag a slider along the pH scale to see examples of solutions at that pH and the concentration of Hâș and OHâ» ions.
Polygon Name Finder - Online How Many Sides?
Enter a number of sides (3â100) and get the correct polygon name (triangle, hectogon). Fun geometry reference.
Easter Date Finder - Online Computus Algorithm for Any Year
Find the date of Easter Sunday for any given year. Learn about the computus algorithm. Simple and accurate.
Function Graph Plotter - Online Math Visualizer 2D
Plot one or more mathematical functions f(x) on a 2D canvas. Zoom, pan, and see intersections. Great for calculus and algebra. Purely clientâside.
Daily Space Picture - Online Astronomy Photo of the Day
View the NASA Astronomy Picture of the Day (APOD) directly in your browser. Read the explanation. No API key needed.
Semaphore Flag Translator - Online Signal Code Converter
Translate text into semaphore flag positions and decode semaphore back to letters. Interactive animated flags. For scouts and maritime fans.
Homophone Checker - Online SoundâAlike Words Tool
Type a word to see all its homophones with definitions. Avoid embarrassing mistakes (their/there/theyâre). Static dictionary.
Pigment Mixing Simulator - Online Color Blending Tool
Mix two or more colors using subtractive (CMYKâlike) blending. See what happens when you combine real paints. Brush effect canvas.
World Flag Quiz - Online Guess the Country by Flag
Random world flags shown; pick the correct country name from four choices. Score and streak. Learn geography.
Periodic Table Explorer - Online Element Facts & 3D Model
Browse a beautifully designed periodic table with electron shell visualization and key facts. Click any element to learn more. Offline ready.
Flame Test Colors - Online Element Identification Chart
Click a metal ion to see the characteristic flame color and wavelength. Useful for analytical chemistry reference.
Paper Fold Simulator - Online Virtual Origami Practice
Fold a virtual square paper step by step with crease lines and visual previews. Practice origami basics without wasting real paper. All canvasâbased.
PRNG Validator - Online Check Randomness Pattern
Paste a list of numbers to visually check uniformity, mean, and simple pattern analysis. Educational tool for statistics and RNG.
Binary to Text Converter - Online Decode Bits to String
Paste binary sequences and convert them back to readable text. Supports space-separated and 8-bit formatted strings. Quick encoding reconversion.
3D Electron Orbital Viewer - Online Chemistry Visual
Rotate and view the 3D shapes of s, p, d, and f orbitals. Great for teaching quantum mechanics. WebGLâbased.
Mandelbrot Set Explorer - Online Infinite Zoom Fractal
Explore the Mandelbrot set with click-to-zoom and vibrant colors. A mesmerizing math journey inside your browser.
Bird Sound Reference - Online Listen & Identify Common Calls
Browse a collection of common bird calls. Play short audio samples to identify birds you hear. Educational static data.
Chemical Equation Balancer - Online Stoichiometry Solver
Enter an unbalanced chemical equation and get the balanced coefficients instantly. Supports parentheses and ions. All local JavaScript algebra.
CSS Grid Playground - Online Interactive Layout Builder
Experiment with CSS Grid properties visually. Add rows, columns, and areas. See the grid in action and copy the code.
Piano Sight Reading Trainer - Online Random Note Staff
A random note appears on the grand staff; click the correct piano key. Improve sheet music reading. Multiple clefs.
Virtual Frog Dissection - Online Biology Anatomy Lab
Stepâbyâstep virtual frog dissection with labeled organs. No mess, ethical. Great for remote learning.
PartsâofâSpeech Tagger - Online Text Analyzer
Paste a sentence and see each word tagged with its part of speech (noun, verb, adjective). Local ruleâbased analysis.
Color Gamut Viewer - Online See sRGB vs Display P3
See the chromaticity diagram and compare sRGB, DCIâP3, and your display. Fun for design geeks.
FizzBuzz Interactive Tester - Online Coding Classic
Run the classic FizzBuzz with custom rules. See the output for any range. A beginner programmer's playground.
Telescope FOV Simulator - Online Eyepiece & View Preview
Select telescope and eyepiece parameters to see the field of view circle on a simulated night sky image.
Tessellation Maker - Online M.C. Escher Style Tiling
Create a simple tessellation by deforming a square or triangle and repeating it across the canvas. Hypnotic patterns.
Conway's Game of Life - Online Cellular Automaton Simulator
Run Conway's Game of Life on a canvas grid. Draw patterns, start/stop the evolution, and adjust speed. A mesmerizing zeroâplayer simulation.
Morse Code Oscillator & Key - Online Practice CW
Use your keyboard or mouse as a straight key. Hear the tone and see the dots/dashes. Perfect for learning CW. Local.
Mental Math Trainer - Online Timed Arithmetic
Solve random arithmetic problems under a time limit. Track your score and improve mental calculation. No data collected.
Random Logic Puzzle Generator - Online Grid Problems
Generate a small logic puzzle grid (like Einsteinâs riddle) with clues. Solve in browser or print. Local generation.
Historical Cameras Timeline - Online Photography Evolution
Scroll through an interactive timeline of cameras from camera obscura to modern DSLR. Photos and facts.
BinaryâDecimal Conversion Quiz - Online Speed Drills
Test how fast you can convert between binary and decimal. Timed drills with increasing difficulty. Learn baseâ2 fluency.
Popover API Demo - Online NoâJS Tooltips & Menus
Test the new HTML popover attribute for creating accessible tooltips, menus, and dialogs without JavaScript. Copy code snippets.
Text to Binary Grid - Online Visual Representation
Enter text and see each character's 8âbit binary laid out in a blackâandâwhite grid. Beautiful data art. Local.
3D RGB Color Cube - Online Interactive Space
Explore the RGB color space as a rotatable 3D cube. Pick a color directly from the volume. Drag to rotate. Canvas 3D.
Solar System Simulator 2D - Online TopâDown Orrery
Watch the planets orbit the Sun in a topâdown 2D view. Adjust speed and zoom. Distances not realistic; beautiful model.